If you charge the two light body suspended on silk threads, touching them with a glass rod, silk worn on, they repel each other. The same is observed if their charge from the ebony stick, worn on the skin. But if one of the bodies charged by the glass rod and the other on the hard rubber, they will be attracted. When electrified bodies repel each other, then we say that charges them a kind, when drawn, the charges of all kinds. Charges of different kinds are called positive and negative. It is considered to be a positive charge, which takes on the glass by rubbing it on the silk. Silk thus acquires a negative charge.

The earth is negatively charged, and a charge equal to 500,000 Coulomb electric charge. Potential difference is the value of the 300,000 volt (300 kV), if we consider the voltage between the positively charged ionosphere and the Earth's surface. There is also a constant current of electricity, of the order of 1350 amperes (A), and the resistance of Earth's atmosphere is about 220 ohms. This gives an output power of about 400 megawatts (MW), which is regenerated by solar activity. This affects the capacity of the earth's ionosphere and to lower layers, which causes a thunderstorm. The electrical energy that is stored and is stored in the earth's atmosphere is about 150 gigajoules (GJ). The system of "Earth-ionosphere" acts as a giant capacitor whose capacitance is 1.8 Farad. Given the huge size of the surface area of the Earth, 1 square meter of surface accounts for only 1 nC electric charge.

When the electric charge carriers is in the electrostatic field, it inevitably becomes effective Coulomb force. This leads to the fact that the charge carrier starts to move in the space, unless the Coulomb force is not compensated by the other, opposing forces. Consider the case where an electric field turned out to be a probe chargeq completely free from the effects of other forces. As soon as the charge will be in the range of the electric field lines, then it will be a force in accordance with the Coulomb law. Suppose that there is a certain amount of space is "filled" by the electric field, that is, is the source of the field and thanks to the long-range, we say that the space is filled with a field. Of course, as a matter no field lines, this imaginary representation in the mind, but in the field of space charge will respond to any manifestation of the Coulomb force. Is it possible to somehow characterize the amount of space energy? Since the electric field is a potential, it is possible to speak of its potential energy.

An important feature of the electric field, as the field has no vortices and created some stationary sources, it is a potentiality. Electric field is called potential if the work that makes the charge carrier in such a field, while moving it in any closed loop is equal to zero. Electrostatic field, ie a field that is formed by the fixed electrical charges, also has similar potentiality. The work of the charge carrier as it moves in a closed circuit in the electrostatic field will be zero. The trajectory of this movement is called closed loop, and this trajectory can be any kind of fundamental importance to its isolation, rather than the form. Potential φ points of electric field is called the work that must be expended to move the charge +q in the amount of Coulomb from infinity to this point of the field, or work on the movement of the same charge +q from that point to infinity.